1. Field of the Invention
This invention relates to a wire harness that is capable of sufficiently maintaining air-tightness between a housing of a connector and a cable and a method of manufacturing the wire harness.
2. Description of the Related Art
Generally, in a wire harness used for vehicles etc., a water proof structure is installed between the housing of the connector and the cable in order to prevent water or the like from entering into the inside of the connector so as to cause a problem.
A conventional wire harness 111 shown in FIGS. 17A and 17B uses a wire seal 114 as the air-tightness maintaining structure.
The wire harness 111 is configured to maintain the air-tightness between the outer housing 113 of the connector 116 and the cable 112 by that a wire seal 114 formed of rubber for waterproofing is inserted between the outer housing 113 of the connector 116 and the cable 112, the wire seal 114 is crushed between the outer housing 113 and the cable 112 so that it is brought into close contact with both of the outer housing 113 and the cable 112.
In the outer housing 113, a cable insertion hole 117 into which an end portion of the cable 112 is inserted is formed, and the wire seal 114 is housed in a wire seal housing concave portion 118 formed in an insertion side of the cable insertion hole 117 of the outer housing 113. An opening part of the wire seal housing concave portion 118 is blocked with a tail plate 115 in order to prevent the wire seal 114 from dropping out.
However, in case of using the wire seal 114 for the air-tightness maintaining structure between the outer housing 113 and the cable 112, it is necessary to install the wire seal 114 corresponding to each of the cables 112 and house each of the wire seals 114 in the wire seal housing concave portion 118, so that in designing, a distance between the cables is broadened and it becomes difficult to shorten a pitch of the cable 112. In particular, the wire harness for vehicles is required to be downsized, so that there is a need for an air-tightness maintaining structure that is capable of further shortening the pitch of the cable 112.
Then, as shown in FIG. 18A, a wire harness 121 is proposed, that is configured to maintain the air-tightness between the outer housing 123 and the cable 122 by that the cable 122 is sandwiched between the outer housing 123 formed of a resin and a welding member 124 formed of a resin, the welding member 124 is welded to the outer housing 123 due to ultrasonic welding by using a horn 125 (for example, refer to JP-A-2000-48901).
As show in FIG. 18 B, the wire harness 121 has a structure obtained by a method that grooves 123a are formed in the outer housing 123 and grooves 124a are formed in the welding member 124 respectively, cables 122 are disposed in the grooves 123a of the outer housing 123 and simultaneously the welding member 124 is stacked from above so as to locate the grooves 124a within positions of the cables 122, and in this condition, the horn 125 is brought into contact with an upper surface of the welding member 124 and is pressed from above down below while the welding member 124 is vibrated, and the welding member 124 is welded to the outer housing 123 due to the ultrasonic welding.
This technique is disclosed in, for example, JP-A-2000-48901 and JP-A-11-66807.